Science Tech

 Molecules Molecule, a group of two or more atoms that form the smallest identifiable unit into which a pure substance can be divided and still retain the composition and chemical properties of that substance. The division of a sample of a substance into progressively smaller parts produces no change in either its composition or its chemical properties … Read more

 Tissue culture Tissue culture, a method of biological research in which fragments of tissue from an animal or plant are transferred to an artificial environment in which they can continue to survive and function. The cultured tissue may consist of a single cell, a population of cells, or a whole or part of … Read more

 Microscope Microscope, instrument that produces enlarged images of small objects, allowing the observer an exceedingly close view of minute structures at a scale convenient for examination and analysis. Although optical microscopes are the subject of this article, an image may also be enlarged by many other wave forms, including acoustic, X-ray, or electron … Read more

 PN Junction Diode A PN-junction diode is formed when a p-type semiconductor is fused to an n-type semiconductor creating a potential barrier voltage across the diode junction The effect described in the previous tutorial is achieved without any external voltage being applied to the actual PN junction resulting in the junction being in … Read more

 Electro magnetic induction When a DC current passes through a long straight conductor a magnetising force, H and a static magnetic field, B is developed around it If the wire is then wound into a coil, the magnetic field is greatly intensified producing a static magnetic field around itself forming the shape of … Read more

 Biopesticides Plants, growing in the wild or in cultivation, face numerous threats from insects, bacteria, viruses, and fungi, as well as from other plants. Biopesticides are inert substances or living organisms that can help protect plants from such threats. Chemical pesticides can offer similar protection but, by contrast, are neither alive nor made … Read more

 Endothermic Reactions Endothermic reactions are those chemical reactions where energy is absorbed by the system from the surroundings mostly in the form of heat. The concept is applied in the physical sciences like chemical reactions where hear is converted to chemical bond energy by way of experiments. Common examples of endothermic … Read more

 Diseases of plants caused by fungi Early Blight of Potato The disease is quite common in India, and occurs on about three week old plants. Since this blight occurs earlier than the ‘late blight’ of potato (caused by Phytophthora infestans), it is called ‘early blight.’ Prevention Measures:   Field sanitation and rotation of … Read more

 Electric discharge in gases Electrical discharge through gases is studied by using a specially designed glass tube commonly called as a discharge tube. It consists of a cylindrical glass tube having a side tube, and two metallic electrodes one at each end. These electrodes can be connected to the respective terminals of a … Read more

 Ray optics Nature of light Light is a transverse, electromagnetic wave that can be seen by humans. The wave nature of light was first illustrated through experiments on diffraction and interference. Like all electromagnetic waves, light can travel through a vacuum. The transverse nature of light can be demonstrated through polarization. Light is … Read more